Semi-automatic feeding attachment for presses.



No. 894,669. PATENTED JULY 2a, 1908 L. 0. KRUMMEL.X SEMI-AUTOMATIC} FEEDING ATTAGHMENT'POR PRESSES.

APPLICATION FILED AUG. 24, 1907.

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PATENTED JULY 28, 1908.

L. 0. KRUMMBL. SEMI-AUTOMATIC FEEDING ATTACHMENT FOR PRBSSES,

APPLIUATION FILED AUG. 24, 1907.

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UNITED STATES PATENT OFFICE.

LOUIS C. KRUMMEL, OF CLINTON, CONNECTICUT.

SEMI-AUTOMATIC FEEDING ATTACHMENT FOR PRESSES.

Specification of Letters Patent.

Application filed August 24, 1907.

Patented July 28, 1908.

Serial No. 390,027.

press operates to cut the parts therefrom.

I call my mechanism semi-automatic, be-

- cause the sheet is first arranged in position by hand, and then is fed step by step, until the parts have been cut from it from end to end, when it is automatically released to drop out.

My invention consists essentially of a suitable supporting standard by which the machine is secured in position on the press, of fixed inclined side-bars, or slide ways, thereon, a sliding frame, grippers on the front lower edge of the frame to grip the sheet, notched racks on the standard, pawls on the frame to engage with the notches and retain the frame temporarily in the various positions, while each part, or series of parts, is being cut and means to release the pawls from each notch when the cut is finished, to permit the frame and sheet to slide down to the next position.

The invention as here illustrated is applied to a press for cutting the circular ends for cans from tin sheets of uniform size, but it will be understood that it is not limited to such use and may be varied in its details of construction, forms of parts, etc. and adapted for similar purposes.

My invention is fully shown in the drawing herewith in which the reference letters and numerals of the description indicate the corresponding parts in all the figures.

Figures 1 and 2 are respectively a top plan and a longitudinal, vertical section of my feeding machine attached to a power press. Fig. 3 is a cross section on line 3-3 of Fig. 1. Fig. 4 is a partial side elevation showing a variation in the means for operating the pawl. Figs. 5 and 6 are res ectively an enlarged plan and longitudina section of the paw% of Fig. 4, which is the preferred form of aw P In the figures 1 indicates the power press, and 2, the plunger thereof carrying a series of punches 3. The press is set on a standard 4 at an inclination as best shown in Fig. 2. 6 6 are the feeding mechanism brackets bolted to the press and connected at their ends by cross-head 7. The brackets are formed as best shown in Fig. 3 to carry notched racks 9 on their inner faces, and the top-plates 10 10 to form slide ways 11 11 for the side-bars 14 14, of the sliding-frame. 12- 12 are tableplates extending from the cross-head 7 to the press to form a table for supporting the sheets of tin A.

The side-bars of the sliding-frame are connected by a cross-bar 16 and by a pawlshaft 17 carrying the pawls 2O fixed thereon, thus permittin the pawls to rock together into and out o the notches a (1 a e. To bar 16 are clamped the fixed lower-jaws 22 of the grippers to which are pivoted the upper-jaws 23, connected by the gripper-pin 24. As here shown, to lugs on the rear ends of the upper-jaws are journaled arms 0 c. p The in 24 may be fixed in the arm 0 and extend fieely through the arm 0 to permit the adj ustment of the grippers at varying distances apart, which is effected by sliding them along the cross-bar 16, and clamping them in posltion by means of the bolts (1. On one, or both, of said arms 0 c (c as here shown) 18 fixed a handle 0, whereby, when turned into position shown in Fig. 2, the cams f on said arms 0 c are turned against the lower-1 aws to close the upper-jaw on the sheet. As here shown the cutting, or stam ing, of the sheet has been completed, but it will be understood that the operation is begun, by the workman drawing the sliding frame rearwardly where it is maintained by the engagement of the pawls with the first notches a, a. The sheet is then secured in the grippers and the ress started. Suitable projections on the grackets or on the racks, might be substituted as equivalents for the notches.

At each stroke thereof, the pawls are disengaged from one pair of opposite notches permitting the frame and sheet to slide forward one space, till the pawls engage in the notches next below. This is effected by means of the tripping-bar 26, which is hung on one side over the path of one pawl, on links 27 27, pivoted to studs g g on the triping-bar and to lugs h h on the bracket, or bracket-cap. The tripping-bar is rocked down at each movement of the punch to trip the pawls by means of a finger 30 which may be arranged on a rock-pin 31, journaled in the post 32 and carrying at its outer end the spring-finger 33, having the pivoted tip j normally held up against a shoulder 7c by a spring m. 36 is a hooked pin adjustably mounted on a bracket 37 on the plunger. As the plunger descends the pin 36 slips by the spring tip j, but when it returns said tip j is rigid against its shoulder in position to be engaged by the hook to rock the rock-pin 31 and rock the finger 30 against the trippingbar, which is thus depressed against the tail a of one of the pawls, whereby both pawls on their shaft 17 are rocked out of the notches and the frame is free to slide down one space. Spring 38 returns the tripping-bar when released to its initial elevated position. Evidently the pawls could be independently journaled, and rocked by separate trippingbars, each operated by a separate pin on the punch, but this would add parts to the ma chine.

The pawl is preferably constructed as best shown in Figs. 5 and 6 with a spring-tip 29, having a shank fitted to a socket in the pawl end and pressed out by a light spring q; the movement of the tips is limited by a lug r fitting to a slot 8. The purpose of this springtip is to insure that the pawl will not return into the same notch from which it has been tripped; it is evident that on withdrawing the pawl from the notch, the spring will expand and force out the tip, so that immediately on the pawl being tripped by the tripper-bar, the tip will engage with the points if elow the notches, insuring the sliding down of the slide to the next lower position.

I prefer the mode of operating the tripperbar on the up or return stroke of the press as described, but in Fig. 4 I have shown a modification in which it is effected by a simpler mechanism and on the down stroke. The fingers 38 etc. are omitted, and, for the hooked pin 36, is substituted a straight pin 40 on the bracket 37, which, as it descends, strikes the tripping-bar. This latter means is simple and operative, but the return of the tripping-bar might not be instantaneous, which is generally desirable.

The mode of operation of the mechanism will be, clear from the preceding descri )tion, except for the last step, where the sliding frame has dropped to the last position with the pawls in notches a and the whole sheet cut into can ends as shown in the drawings. When the slide is in this position the notch v on the tripping-bar is immediately over the pawl end n so that the bar does not strike the tail and release the pawl. In the same position, the gripper-pin 24 has come under a stud, or projection, 42 on the plunger, and, as the plunger descends to cut the final series of blanks from the sheet, the gripper-pin is struck and rocked by the said stud to turn the locking cams, unlocking the jaws and releasing the sheet, which then is free to dro out. The slide is then free to be drawn baclf to the upper rear end of the slide-ways ready to receive another sheet.

Having thus described my invention, what I claim and desire to protect by Letters Patent, is 7O 1. In a mechanism of the character described, a punch-press set on an inclined standard, brackets secured on the-standard and downwardly inclined toward the press, racks secured on the brackets and having series of notches arranged in corresponding pairs on their upper edges, a sliding-frame fitted to the brackets, pawls journaled on the frame and adapted to engage with the notches to grip the sheet to be punched, grip 89 pers secured on the front of the frame and means connected to the punch of the press to disengage the pawls from the pairs of notches permitting the frame and grippers to slide downwardly and forwardly one space until gr the pawls engage with the next pair of notches, said notches being suitably spaced on the racks to permit uncut portions of the sheet to be in position for the punches at the next stroke.

2. In a feeding mechanism of the character described, an inclined standard, a punchpress set thereon, parallel side brackets for the feeding mechanism suitably supported adjacent to the press, said brackets being in- 92" clined toward the press, racks secured to the brackets and having a series of notches on each rack, the notches on each side being arranged opposite and being suitably spaced to correspond to the diameter of the punches 1 9 and of the parts to be cut, a sliding-frame fitted to the brackets and adapted to slide downwardly and forwardly toward the press, grip ers on the front of the frame, means to c ose the grippers to grip the sheet, 5 pawls ournaled on the frame and adapted to engage with the notches, a connection between the pawls, a tripping-bar hung on one bracket above the path of one pawl, and means operated by the punch to depress the no tripping-bar into engagement with one pawl at each stroke of the punch to disengage the pawls from the notches.

3. In a mechanism of the character described, a )unch-press set an an inclination on a suitable standard, parallel side brackets secured on the press and inclined down.- wardly toward the press, ratchets secured to the brackets and correspondingly notched, a sliding frame fitted to the slide-ways on the brackets, grippers on the front of the frame adapted to grip the sheet, a pawl-shaft journaled in the frame, pawls secured. on saidv shaft and adapted to engage with the notches,

a tripping-bar hung 011 links on one bracket and arranged above the path of one pawl, a post adjacent to the front end of the trippingbar, a rock-pin journaled in the post and extending over the tripping-bar, a rearwardly projecting finger on the rock-pin resting adjacent to the upper surface of the tripping-bar, a forwardly ro'ectin s rin finger onthe rock-pin, a shbuldei oil tll e spring-finger, a ti pivoted to the springfinger, a springho dlng said ti up against the shoulder, a bracket on t e punch, a hookedpin adjustably mounted on said punch bracket, said hookedpin being arranged to depress said pivoted tip on the down stroke of the punch, but to engage with the tip and rock the first finger against the tripping-bar on the up stroke of the unch, and a spring to restore the tri pingar to its initial upper position, su stantially as shown.

4. In a feeding mechanism for metal sheets, the combination with a punch-press, of supporting brackets downwardly inclined toward the press, a sliding frame fitted to said brackets and adapted to slide down thereon toward the press, retaining means to retain the frame in a plurality of positions on the brackets, and means automatically operated by the punches to disengage said retaining means at each stroke of the press and permit the frame to slide down to the next position.

5. In a feeding mechanism for metal sheets, the combination with' a suitable standard, of inclined brackets on the standard, notched racks on the brackets, a sliding frame, fitted to slide on the the brackets, pawls pivotally secured on the frame to engage with the notches, means automatically to disengage the pawls temporarily from the notches, and grippers on the front of the frame to grip the sheet.

6. In a feeding mechanism for metal sheets, the combination with a punch-press, of parallel brackets suitably supported and downwardly inclined toward the press, notched racks on the brackets, a sliding frame fitted to the brackets, pawls on the frame to engage with the notches, grippers on the front of the frame to grip the sheets and means operated by the press at each stroke to disengage the pawls from the notches permitting the frame, to slide down wardly toward the press.

7. In a feeding mechanism for metal sheets the combination with a suitable standard, of inclined brackets secured on the standard, notched racks secured on the brackets, a sliding frame fitted to the brackets, pawls on the frame to engage with the notches, and means on the frame to engage with the sheet.

8. In a feeding mechanism for metal sheets, the combination with a punch-press, of brackets suitably supported and downwardly inclined toward the press, notched racks secured on the brackets, a sliding frame fitted to the brackets, engaging means on the frame to engage with the notches, means on i the frame to grip the sheets, and means operated by the punch press at each stroke to release said engaging means from the notches, permitting the frame to slide down, one space at each stroke.

9. In a feeding mechanism for metal sheets, the combination with a punch-press, of opposite, parallel brackets rearwardly eX- tending from the press and downwardly inclined toward the press, racks on the brackets formed each with a series of notches, the corres onding notches in the respective racks being arranged oppositely, of a sliding frame fitted to the brackets, a pair of opposite pawls pivotally secured on the frame and adapted to engage with the notches, and a positive connection between the pawls, and means operated by the press to engage with one pawl and disengage the pawls from the respective notches.

10. In a feeding mechanism for metal sheets, the combination with a punch press, of a support for a sliding frame downwardly inclined toward the press, racks secured on said support and provided with a series of notches, said notches being arranged oppositely on the respective racks, a sliding frame fitted to said support and adapted to slide down thereon step by step, opposite pawls on the frame adapted to engage with the notches in the respective racks, a positive connection between the pawls, a tripping bar hung on the support and means operated by the press to force the tripping bar against one of the pawls in the successive positions of said pawl and frame to disengage the pawls from the notches and permit the frame to slide down one step.

11. In a feeding mechanism for metal sheets, the combination with a punch-press, of brackets downwardly inclined toward the press, racks on the brackets, said racks bein formed with series of uniformly spaced notches, correspondingly arranged in pairs on the opposite racks, a sliding frame fitted to the brackets, pawls on the frame to engage with the notches, means to disengage the pawls from each pair of notches in succession permitting the frame to slide down step-bystep, grippers on the front of the frame to grip the sheets and means operated by the press, when the frame is in the lowest position, to loosen the grippers and permit the waste of the sheet to dro out of the press.

12. In a mechanism 0 the character described, the combination with a punchpress, of brackets suitably supported and inclined downwardly toward the press, notched racks on the brackets, a sliding frame fitted to the brackets, a pawl-shaft journaled in the frame, pawls secured on said shaft and having their lower ends adapted to engage with the notches, spring-tips having shanks fitted to sockets in the ends of the pawls, springs in said sockets to press the spring-tips outwardly, pins in the pawl to engage with short slots in the spring-tip shanks, and means operated by the punch-press to engage with one pawl and disengage the pawls from the notches.

13. In a mechanism of the character described, the combination with a punchpress, of brackets secured on the press and inclined. downwardly toward the press, notched racks on the brackets, a sliding frame fitted to the brackets, a cross bar at the front end of said frame, lower gripperjaws clamped on said cross-bar and laterally adjustable thereon, upper jaws pivoted to the lower jaws, arms journaled to lugs on the rear ends of said upper jaws, cams on said arms to engage with the lower jaws, a handle on one of said jaw-arms to turn the cams against the lower jaws, a gripper pin fixed in one of said jaw-arms and extending through a suitable hole in the other j aw-ar'm, pawls on the frame to engage with the notches, means operated by the press to disengage the pawls from the notches, and a downwardly depending stud on the punch adapted to engage with the gripper-pin, when the sliding-frame has moved down into forward position adjacent to the press, to rock the jaw-arms and cams and unlock the gripperjaws, substantially as shown.

14. In a feeding mechanism for metal sheets, the combination with a punch press, of brackets secured on the punch-press, a sliding frame arranged on the brackets, grippers on the front of the frame adapted to grip the sheet, gravity means to move the frame step by step toward the punches to feed the sheet thereto, and releasing means carried on the press automatically to engage the grippers and release the sheet when the frame is in its extreme forward position.

15. In a feeding mechanism for metal sheets, the combination with a punch press having a suit, ble standard, of a sliding frame suitably arranged in relation to the press, grippers carried on the frame to grip the sheet, means operative on the up stroke of the press to advance the sheet step by step and releasing means to open the grippers and release the punched sheet operative when the frame has been advanced to its extreme forward position.

16. In a feeding mechanism for metal sheets, the combination with a punch-press having a suitable standard, of supporting brackets secured to the standard, a pawl actuated sheet-feeding mechanism arranged on the brackets, the pawl, a trip-bar, suitably hung and adapted to release the pawl [when depressed, a depressing linger in contact with the trip-bar, a latch on the linger to engage the mnehpresS and operative on the up stroke thereof.

17. In a feeding mechanism for metal sheets in combination with a punch-press having a suitable standard, of a sliding frame suitably arranged in relation to the press, grippers carried on the frame, means tending to advance the frame, a pawl actuated frame releasing mechanism adapted to allow the frame to advance step by step to feed the sheet, a trip bar suitably hung and adapted when rocked to engage and release the pawl, said trip-bar operative inv all but the extreme forward position of the frame, and conneetions between the trip-bar and the punch press to rock the bar after each successive operation of the press.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

LOUIS C. KRUh'tMEL.

Witnesses AGNEs KRUMMEL, LILY RICHTER. 

